Boy, the market has sure been fun for those of us who held on to our stocks (or bought more of them) two years ago, when it looked like the financial world might be coming to an end.

Rather than collapsing, the U.S. stock market took off on a tremendous run. The Dow industrials closed Thursday 84 percent above their level on March 9, 2009. The Standard & Poor’s 500-stock index was up 93 percent. The total-market Wilshire 5000 index? Up 102 percent. Sweet.

But a considerable part of the market has done even better. I’m talking smaller-capitalization stocks, or those with relatively small stock market values. The little-known Wilshire 4500 index — which consists of the total U.S. market minus the 500 stocks with the greatest market value — is up an amazing 133 percent since the market hit bottom in March 2009.

What’s more, even though the Dow, S&P and Wilshire 5000 are still considerably below their peaks of October 2007, the 4500 has set new highs, one after another. It closed last Friday an eyelash below the record high it had set Thursday.

“Smaller-cap companies led the way down and have led the way back up,” says Bob Waid, managing director of Wilshire Analytics. Not only has the 4500 set records, he said, but so have Wilshire’s mid-cap and small-cap indexes, which are more familiar as asset classes than the 4500.

Waid has some other interesting numbers to share, as well. It turns out that relative to corporate profits, the S&P and the 5000 are close to the levels reached when these indexes hit all-time highs. The S&P sells at 17.1 times earnings now, compared with 17.9 on Oct. 9, 2007. The comparable numbers for the 5000 are 18.6 and 19.5.

No, I’m not trying to tell you that these price levels mean that the stock market is now at bubble levels, or that a “correction” (a ridiculous Wall Street euphemism that means “big price drop”) is coming.

What I’m trying to do is have us walk through some numbers together. And just because stocks are expensive by one measure doesn’t necessarily mean they’re overpriced.

For instance, if you look at so-called forward price-to-earnings ratios — today’s stock prices divided by the earnings analysts expect companies to post in the coming year — the S&P and 5000 are about 10 percent below their peak 2007 levels. (If you really want to know: On Thursday, the S&P and 5000 forward P/Es were 13.3 and 14, respectively, compared with 15.1 and 16 on Oct. 9, 2007.)

If you accept the argument that stock prices are about the future, not the past, forward P/E is a more relevant number than regular P/E, which is based on the past 12 months of profits.

So what’s my prediction? Sorry, I haven’t got one. If I knew what the stock market was going to do, I’d be a billionaire investor managing his own account, not a business writer.

What I do know, though, is that as stocks are becoming considerably more expensive, another asset class—U.S. Treasury securities with maturities of two years and up—is getting cheap.

This is the reverse of the situation two years ago, when stocks were shunned and Treasuries were embraced as a “safe haven,” their low yields notwithstanding. If you look at bond price tables, though, you’ll see that they’ve not been safe. They’ve suffered market-price declines that exceed the interest their owners have received.

The point of this exercise: Stocks look a lot less interesting as an investment than they did when almost no one wanted them, and Treasury securities look a lot more interesting than they did when everyone wanted them.

I’m not running out to dump my stocks and buy bonds, and I’m not suggesting that you should. But I’m thinking differently about the relative values of stocks and Treasuries than I did a few months ago. You might want to do the same.

asloan@fortunemail.com

Allan Sloan is Fortune magazine’s senior editor at large.

Allan Sloan is a columnist for The Washington Post. He is a seven-time winner of the Loeb Award, business journalism's highest honor.

Comments our editors find particularly useful or relevant are displayed in Top Comments, as are comments by users with these badges: . Replies to those posts appear here, as well as posts by staff writers.

To pause and restart automatic updates, click "Live" or "Paused". If paused, you'll be notified of the number of additional comments that have come in.

Comments our editors find particularly useful or relevant are displayed in Top Comments, as are comments by users with these badges: . Replies to those posts appear here, as well as posts by staff writers.